Latch operating means



Aug. 1, 1933. N. R. KIRK 1,920,858

LATCH OPERATING MEANS Filed June 16, 1932 y Iliiii |ll f7 if s Patented Aug. 1, 1933 LATCH OPERATING MEANS Noel n. Kirk, Tientsin, china Application June 1s, 1932. serial No. 617,671

3 Claims.

This invention relates to latch operating means and more particularly to a novel means adaptedy automatically to retract a door latch while the associated door is being moved to closed position under the retarding action of a door check.

As is well known, it is common practice to provide doors with automatic closing devices, usually spring operated, in connection with a door check for retarding the closing action so as toprevent slamming. Many kinds of combined closers and door checks'have been known for a long time and are today in extensiveuse. Most of these devices include a spring for moving the door to closed position and a piston operating against uid pressure, either pneumatic or liquid, for retarding the closing action and preventing slamming of the door. v Usually the piston acts against a body of uid which is allowed to escape so asl to permit the piston to advance, and, by Varying the rate at which the Iiuid can escape, the eiective retarding action produced 'and consequently the closing speed of the door can be varied.

In many cases it is found that, when the adjustment of the uid escapement is such as to retard Ithe closing action to the desired degree, the action of the closing spring is not strong enough to cause the door latch to be cammed inwardly, i. e., to be movedl into retracted lposition by engagement with the keeper. This results in the doors being held open slightly. If the closer or check is so adjusted as to permit the `door to close with suflicient speed to cause retraction of the latch upon engagement of the latter with the keeper, an objectionably hard slam results.

An` object of the present invention is to provide means actuated under the control of a door check for maintaining the latch in retracted position so as to permit a very slowand quiet closing of the `door yet assuring complete closing thereof with subsequent automatic operation of the latch into projected position in engagement with the keeper. Other and more specic objects will become apparent from the following detailed description, the appended claims, and the accompanying drawing, in which:

v Figure 1 is a perspective view of a door showing one form of latch operating means embodying the invention applied thereto;

Figure-2 is a vertical sectional view ota latch` mechanism and operating mechanism therefor, parts being shown in elevation;

Figure 3 is a vertical sectional view of aconventional form of combined door closer and check;

Figure 4 is atop plan view of a latch mechanism and associated keeper shown as applied to adoor and door frame, the latter parts being shown in horizontal section.

Generally stated, my invention includes means associated with a door latch and being operable under the control of a door check for maintaining the latch in retracted position during closing of the door and until the latch has swung past the keeper. Preferably, the latch operating means is responsive to the retarding pressure in a fluid pressure controlled door check, the pressure medium employed being either air or liquid, as may be desired.

A practical embodiment of the invention is illustrated in the' accompanying drawing, in which I `have shown a door A as being hinged at l to a door frame B. The door is provided with latch casing 2 for limiting outward movement of the latch bolt. A spindle 10 is journaled in the casing at right angles to the latch 3 and is provided with upper and lower cam parts l1 and 12 adapted to cooperate with a downwardly extending projection 13 of the latch bolt for retracting the latter upon rotation of the spindle in either direction. A keeper 14 is secured to the door frame B and is provided with an opening 14a adaptedvto receive the latch bolt nose 4. The latch bolt shown and described herein is of a simple conventional form, and it will be understood that the specic construction thereof forms no part of my invention, nor is it necessary that my invention be used in connection with latch mechanisms of this specific nature.

lFor automatically closing the door at a desired retarded rate, I have provided a combined door closer and check generally designated D. This closer and check includes a casing 15 secured to the door by means of screws 16 and being formed with a spring chamber 17 and a cylinder 18 extending at right angles to the spring chamber 17. A vertical shaft 19 extends upwardly through the spring chamber and is provided with a crank arm 20 pivotally connected to a link 21 which in turn is pivotally connected to a bracket 21e a crank 25 secured to the lower end of the shaft 19. When the door is in open position, thepiston 23 will be to the left of the positionshown in Figure 3. When the door is moved towards its closed position under the action 'of the spring 22, the piston 23 will be forced to the rightby rotation of the shaft 19 and the crank 25 and will force` fluid contained in theoright.hand end of the cylinder 18 .through a restricted passage 26,

the resistance offered by thel fluid acting toire-A tard the closing movement-of .the door... A needle valve 27 interposed in the restricted vpassage 26 serves. as a means tov vary the rate at-which uid canfbe `forced through the passage,v and,conse quently provides for the regulation of the closing speed ofthe door.` When the door .is being I n moved toppen position, the-piston ,23 will move to the 'left and a ball check valve 28 provides relatively open vcoxnmunication .between kthe cylinder on opposite sides or the piston so as `tore,-` duce toa minimum-the resistance Aoiered to Aopening OftheQl y. ''ll'dOQr, @loser and door Check described above are,of conventional form and are more specifically described in the.V United States LettersPatent to Taylor-730,i1l7, of June 9, .1903.

It will'l be -understood that 4the, specific construction of door closer and check does not per se -con e stitute mynvention, ,and that my invention may becemployed, inconnectionwith door checks of other speci'iicconstructions.: c c l f f @Considering the structure described so far and assuming that theneedle-valve 21` is adjusted in such a'A manner as to permita closing speed which will not resultinan undesirable slam, the spring- 22j will V`rn`ove the door toward its closed position underv the retardingaction of the Vfluid escaping through the passage 26.. When the latch bolt nose 4 engages the keeper 14 as shown in Figure 4, the

resistance to the retraction ofthe latch bolt offereld by the spring. 6 will inmanycases stop further movement of the door. s o lthat it wil1 come to rest before being closed completely.' On the otherfhand, if l'it'is assumed that the needle valve 27'is so adjustedtfas to'permit a more rapid closing of .thefdoorin order that 4retraction of the latch bolt assured, anobjectionable slam will result.,

veryslow closing ofl the door and vyet to assure complete closing of. the latter, AI- provide means for automatically-retracting thedatch bolt durt ingxthe closin'gmovement of` the vdoor and for automatically allowing thefbolt to be projected by.

thel spring `@after theflatch bolt nose has been moved into registry with the openingliafin .the keeper; In the construction shown, the bolt is providedfwith a tail or extension 29which projects through' an opening 3,0 inthe latch casing, and whichA is formed v with a reduced rear en`d portion 31 and witha'n upwardly extending, projection or lug 32 atthe extreme rear end of the latchbolt tail. A cylinder [33,is secured to the door by'means of screws 34,l and mounted in the cylinder is a piston 35 provided with a stem 36 In order.. to an adjustment c eiiecting a "the -end nearest the latch mechanism, and the -right hand or pressure end of the cylinder 18 of the door check. A vent 42 is provided in the vright hand end of the cylinder 33 so as to prevent .the entrapping of air therein, which would have a dash pot eiect and interfere with the operation of thefpiston 35.

It will be noted that the plug 32 on the latch bolt tail and the extension 38 on the piston stem 36 provides .a lost motionvconnection between the piston 35 and the bolt. By virtue of this connection,` whenever the piston 35 ismoved to the right, the latch bolt vwill lbe retracted, butassuming, the parts to be Vinvtheir Figure 2 orfnor-y mal positions, the latch bolt may-be retracted by operation of the spindle 10 without its being necessarytomove the piston 35.

The operation of the .latch operating means will be described briefly. Assuming that the door isopen and that ythe needle valve 27 is so adjusted as kto permita restricted rateof ilow through the paSSage 26- so as to effect a -very slow closingoi' the door,- the spring r22 willmove the door slowly towardits closed position against xthe resistance offered by. the rluid escaping. in advance of the piston 23. vvThe piston acting against the body of iluid andthe iiuid; escapingthrough the small opening presentedby the valve 2'( will result in pressure-being built, up in the right hand end oi.' the cylinder- 18, and this, pressure ywill be com'- municated through thev pipe listo-the left hand end of the cylinder 33, where it will act upon the piston 35 andv move thelatterto the right. The projection 38.0n the piston stem 36 will engage the lug 32 on= the-latch bolt tail and .willfmove the bolt to retracted-position. The bolt will be main-y tained in retracted position vas long as the spring 22 is moving the door to closed position against the pressure ofzthe fluid. As soon as the door isclosed `completely so that no` further movement of thepiston 23 can takeplace, the pressure in the cylinder 18, the pipe Y41, and the cylinder 33 will diminish, and the springs 6 and 39 will return the bolt andpiston35 to, the Figure 3posi tions, in which the bolt nose will extend into the openingv 14a of the keeper. Thus, through the provision of my improved latch operating means, the door may be closed veryslowly so as to prevent the occurrencel ofobjectionable slams, yet complete closing of the door'isassured because of the fact'that the latch boltinose is maintained retracted during the: entire: closing movement, and hence. cannot act tozarrest-'closing of the door until it is completed. i

`lilthough.- the form of apparatus illustrated and described herein is considered to embody the invention in a practical form, .it will be understood that` various modications may be made in the specic v'construction and arrangement of the parts without departing from the spiritof the invention as defined in the claims.

Iclaimr'A -v 1. The combination of a door latch bolt; manually operable means operatingly connected to the latch bolt for actuating the latter; a door closer; a fluid pressure controlled door check, both associated with said latch; a cylinder; means affording communication between said cylinder and said door check; a piston mounted in said cylinder; and a lost motion connection between said bolt and piston.

2. The combination with a door, of a door latch bolt; a door closer adapted constantly to urge said door to closed position; a iluid pressure controlled door check connected to said door, said check including a check cylinder and a check piston; a latch cylinder; a latch piston operable therein and being connected to said latch bolt; and means forming a passage providing constantly closed communication between said check cylinder and said latch cylinder.

NOEL R. mK. 

